1. Field of the Invention
The present invention relates to a multi-air conditioner, and more particularly, to a simultaneous heating and cooling operation type multi-air conditioner.
2. Discussion of the Related Art
Generally, an air conditioner is an apparatus for cooling or heating an indoor space such as a residential space, office, restaurant and the like, and is provided with a compressor and a heat exchanger to cool or heat indoor space by flowing refrigerant.
The air conditioner has been advanced to the development of a multi-air conditioner performing the heating and cooling operations at the same time so as to maintain more pleasant indoor environment without being affected by an outdoor temperature or environment, so that it becomes possible to cool or heat all the rooms in the same operation mode.
In the meanwhile, the multi-air conditioner is comprised of one outdoor unit, and a plurality of indoor units each being connected to the outdoor unit and being installed every room. The multi-air conditioner operates in one of heating mode and cooling mode, thereby heating or cooling the room air.
However, as the indoor space is widened, the indoor structure is complicated and the position or use purpose of each room is diversified, the temperatures of the respective rooms become different. In other words, a room in which a machinery or a computer system is installed shows a higher temperature than other rooms due to heat generated during an operation of the machinery or the computer system.
Accordingly, some rooms may be required to operate in a cooling mode while other rooms may be required to operate in a heating mode. However, the conventional air conditioner has a drawback in that it does not meet such a requirement.
According to the aforementioned necessity, there is being requested a development of a simultaneous cooling and heating type multi-air conditioner in which the rooms needing the cooling operation are operated in the cooling mode and at the same time the rooms needing the heating operation are operated in the heating mode.
Also, in the conventional multi-air conditioner, since refrigerant flowing through an identical position of each pipe in the cooling mode and the heating mode shows states that are different depending on the operation condition, i.e., states that phase and pressure are different, there is a problem in that an excessive safety rate in designing the diameters of the pipes is applied.